/* Define a professional color palette and font settings */
:root {
    --color-primary: #0f172a; /* Slate 900 - Dark Blue/Black */
    --color-secondary: #1e40af; /* Blue 700 - Accent Blue */
    --color-background: #f8fafc; /* Slate 50 - Off-White */
    --color-card-bg: #ffffff;
    --color-border: #e2e8f0; /* Slate 200 */
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--color-background);
    color: var(--color-primary);
}
.container {
    max-width: 1200px;
}
.header-section {
    background-color: var(--color-primary);
    color: white;
    padding: 2rem 1rem;
    border-radius: 0.75rem 0.75rem 0 0;
    box-shadow: 0 10px 20px rgba(15, 23, 42, 0.5);
    margin-bottom: 2rem;
}

/* Desktop header padding */
@media (min-width: 768px) {
    .header-section {
        padding: 4rem 1.5rem;
    }
}
/* Performance optimizations */
.card {
    background-color: var(--color-card-bg);
    border-radius: 0.75rem;
    box-shadow: 0 5px 15px -3px rgba(0, 0, 0, 0.05);
    padding: 2.5rem;
    margin-bottom: 3rem;
    border: 1px solid var(--color-border);
    will-change: transform, opacity; /* Optimize for animations */
}

/* Mobile Schedule Cards */
@media (max-width: 767px) {
    .card {
        padding: 1.5rem;
        margin-bottom: 2rem;
    }
}

/* Sticky Navigation */
.sticky-nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    background-color: rgba(255, 255, 255, 0.95);
}

.sticky-nav.scrolled {
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.nav-link {
    position: relative;
    transition: all 0.3s ease;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background-color: #1e40af;
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* Hero CTA Button Enhancements */
.hero-cta-primary {
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%);
    box-shadow: 0 10px 25px rgba(220, 38, 38, 0.3);
}

.hero-cta-primary:hover {
    background: linear-gradient(135deg, #b91c1c 0%, #991b1b 100%);
    box-shadow: 0 15px 35px rgba(220, 38, 38, 0.4);
}

.hero-cta-secondary {
    border: 2px solid rgba(147, 197, 253, 0.8);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.1);
}

.hero-cta-secondary:hover {
    background: rgba(147, 197, 253, 0.9);
    border-color: rgb(147, 197, 253);
}

/* Schedule Table Styling */
.daily-schedule-table {
    border-collapse: separate;
    border-spacing: 0;
    overflow: hidden;
    border-radius: 0.5rem;
}
.daily-schedule-table th, .daily-schedule-table td {
    padding: 1.25rem 1rem;
    text-align: left;
    border-right: none;
    /* Ensure all content in td is normal weight */
    font-weight: 400;
}
.daily-schedule-table th {
    background-color: #e0e7ff; /* Indigo 100 */
    color: var(--color-secondary);
    font-weight: 700;
    border-bottom: 2px solid var(--color-secondary);
}
.daily-schedule-table td {
    border-bottom: 1px solid var(--color-border);
}
.daily-schedule-table tr:last-child td {
    border-bottom: none;
}

.day-highlight {
    background-color: #f0f4ff; /* Lighter Indigo for day labels */
    font-weight: 800;
    color: var(--color-primary);
}
/* Specific rule to prevent bolding of any kind inside table cells */
.daily-schedule-table td strong {
     font-weight: inherit !important;
}

/* Accessibility: Focus styles */
a:focus, button:focus, input:focus, textarea:focus, select:focus {
    outline: 3px solid #1e40af;
    outline-offset: 2px;
    border-radius: 4px;
}

/* High contrast focus for better visibility */
.nav-link:focus {
    outline: 3px solid #1e40af;
    outline-offset: 2px;
    background-color: rgba(30, 64, 175, 0.1);
}

/* Skip link for keyboard users */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: #1e40af;
    color: white;
    padding: 8px;
    text-decoration: none;
    border-radius: 4px;
    z-index: 1000;
}

.skip-link:focus {
    top: 6px;
}

/* Screen reader only text */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Better color contrast for links */
a {
    color: #1e40af;
}

a:hover, a:focus {
    color: #1d4ed8;
}

/* Ensure minimum touch targets */
@media (pointer: coarse) {
    .nav-link, button, a {
        min-height: 44px;
        min-width: 44px;
    }
}

/* Mobile responsiveness improvements */
@media (max-width: 768px) {
    .daily-schedule-table {
        font-size: 0.875rem;
    }
    .header-section {
        padding: 2rem 1rem;
    }
}

/* Interactive Elements & Micro-interactions */
.info-card {
    transition: all 0.3s ease;
    cursor: pointer;
}

.info-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

/* Icon List Styling */
.icon-list-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 0;
}

.icon-list-item svg {
    flex-shrink: 0;
    width: 1.25rem;
    height: 1.25rem;
}

.icon-list-item span {
    line-height: 1.4;
}

.lecturer-card {
    transition: all 0.3s ease;
}

.lecturer-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

.lecturer-card:hover .lecturer-number {
    transform: scale(1.1);
}

/* Enhanced Button Interactions */
.btn-enhanced {
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}

.btn-enhanced::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.btn-enhanced:hover::before {
    left: 100%;
}

/* Pulse Animation for Important Elements */
@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.cta-pulse {
    animation: pulse 2s infinite;
}

/* Ripple Effect */
.ripple {
    position: absolute;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.6);
    transform: scale(0);
    animation: ripple 0.6s linear;
    pointer-events: none;
}

@keyframes ripple {
    to {
        transform: scale(4);
        opacity: 0;
    }
}

/* Optimized animations for better performance */
.animate-in {
    animation: fadeInUp 0.4s ease-out forwards;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Reduce animation complexity for better performance */
.card:nth-child(1) { animation-delay: 0.05s; }
.card:nth-child(2) { animation-delay: 0.1s; }
.card:nth-child(3) { animation-delay: 0.15s; }
.card:nth-child(4) { animation-delay: 0.2s; }

/* Mobile Schedule Cards - Cleaner Design */
@media (max-width: 767px) {
    .schedule-day-card {
        background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
        color: #1e293b;
        border-radius: 16px;
        padding: 1.5rem;
        margin-bottom: 2rem;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
        border: 1px solid #e2e8f0;
        transition: all 0.2s ease;
    }

    .schedule-day-card:hover {
        transform: translateY(-2px);
        box-shadow: 0 6px 16px rgba(0, 0, 0, 0.12);
    }

    .schedule-day-title {
        font-size: 1.125rem;
        font-weight: 600;
        margin-bottom: 1.25rem;
        text-align: left;
        color: #1e293b;
        border-bottom: 2px solid #cbd5e1;
        padding-bottom: 0.75rem;
    }

    .schedule-session-card {
        background: white;
        color: #374151;
        border-radius: 12px;
        padding: 1.25rem;
        margin-bottom: 1rem;
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
        border: 1px solid #f1f5f9;
        border-left: 4px solid #3b82f6;
        transition: all 0.2s ease;
    }

    .schedule-session-card:hover {
        transform: translateY(-1px);
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        border-color: #60a5fa;
    }

    .schedule-session-title {
        font-weight: 600;
        color: #1e40af;
        margin-bottom: 0.75rem;
        font-size: 1rem;
    }

    .schedule-session-content {
        font-size: 0.875rem;
        line-height: 1.6;
        color: #475569;
    }

    .schedule-session-content ul {
        margin-top: 0.75rem;
        padding-left: 1.25rem;
    }

    .schedule-session-content li {
        margin-bottom: 0.5rem;
        padding-left: 0.25rem;
    }

    /* Remove hover effects on touch devices */
    @media (hover: none) and (pointer: coarse) {
        .schedule-day-card:hover,
        .schedule-session-card:hover {
            transform: none;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
        }
    }
}